Damned, cloud-init is messing with /etc/hosts...

roles/common/tasks/main.yml

@@ -4,20 +4,31 @@
   hostname:
     name: "{{ inventory_hostname_short }}"
 
-- name: Configure localhots
+- name: Configure localhost
   lineinfile:
     path: /etc/hosts
     regexp: '^127\.0\.0\.1'
     line: "127.0.0.1 localhost"
-    owner: root
-    group: root
-    mode: 0644
 
 - name: Configure FQDN
   lineinfile:
     path: /etc/hosts
     regexp: '^127\.0\.1\.1'
     line: "127.0.1.1 {{ inventory_hostname }} {{ inventory_hostname_short }}"
+
+- name: Check if cloud-init is installed
+  ansible.builtin.stat:
+    path: /etc/cloud/cloud.cfg.d/
+  register: cloud_cfg
+
+- name: Stop cloud-init to change hostname and /etc/hosts
+  when: cloud_cfg.stat.isdir is defined and cloud_cfg.stat.isdir
+  copy:
+    content: |
+      # Managed by Ansible
+      preserve_hostname: true
+      manage_etc_hosts: false
+    dest: /etc/cloud/cloud.cfg.d/02_ansible.cfg
     owner: root
     group: root
     mode: 0644

roles/exim4/defaults/main.yml

@@ -1,5 +1,5 @@
 ---
-exim4_sendonly_fqdn: '{{ ansible_fqdn }}'
+exim4_sendonly_fqdn: '{{ inventory_hostname }}'
 
 exim4_sendonly_smarthost: ''
 exim4_sendonly_username: ''